#!/bin/bash

# Rename patch files according to the Content-Disposition header line
# if they do have one, or Subject if they don't.
#
# Copyright (C) 2005, 2006  Jean Delvare
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
# as published by the Free Software Foundation; either version 2
# of the License, or (at your option) any later version.
# 
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details:
# http://www.gnu.org/copyleft/gpl.html

#
# original found at http://jdelvare.pck.nerim.net/linux/rename-patch
#

findname()
{
	local file=$1 pattern;

	# Try Content-Disposition first
	pattern='^Content-Disposition:[[:space:]]*inline[[:space:]]*;[[:space:]]*filename[[:space:]]*=';
	if grep -q $pattern "$file"
	then
		sed -ne "/$pattern/{s/$pattern[[:space:]]*//p;q}" "$file"
		return
	fi

	# Fallback to Subject
	pattern='^Subject:';
	if grep -q $pattern "$file"
	then
		sed -ne "/$pattern/{
			s/$pattern[[:space:]]*//;
			s/\[[^]]*\]//g;
			s/([^)]*)//g;
			s/[^a-z0-9._-]/-/ig;
			s/--*/-/g;
			s/^--*//;
			s/[.-]*$/.patch/;
			p;q}" "$file" | \
		tr A-Z a-z
		return
	fi
}

for file in $@
do
	name=$(findname "$file")

	if [ -z "$name" ]
	then
		echo "No name found for $file" >&2
		continue
	fi

	if [ "$name" == "$file" ]
	then
		# It's already OK
		continue
	fi

	if [ -e "$name" ]
	then
		echo "Can't rename $file to $name which already exists" >&2
		continue
	fi

	mv -f "$file" "$name"
	echo $name
done